Carrier tube



G. T. SMITH CARRIER TUBE Filed Feb. 25, 1958 INVENTOR Gus 7T .SmE-H BYZ/ ,fl, $141+ Va.

ATTORNEY fjl.

A ril 4, 1961 United States Patent CARRIER TUBE Gus T. Smith, Padncah,Ky., assignor to Ace Engineering Company, Paducah, Ky.,'a corporation ofKentucky Y .Filed m. 25, 1958, Ser. No. 717,366 4 Claims. (Cl. 66-126)of steels, is widely recognized and has been the source of difiicultiesin the production of fabrics which should be knit with uniform yarntension, as well as the cause of interruptions in production in order torenew worn guides which cause uneven tension in the yarn. Wherepossible, yarn guides have been made, at least in part, from ceramicmaterial, as the extreme hardness and smoothness of the ceramic betterresists wear by the yarn. In the past, attempts have been made tofashion a carrier tube from ceramic, but have been generallyunsuccessful due to the fact that the carrier tube is subjected tovibrations and strains in the knitting machine which cause a ceramictube to fracture.

One of the principal purposes of the present invention is to provide animproved carrier tube which consists of a metal sleeve which receivesannular ceramic inserts at either end, which are thus located in thearea where the BCQ,

ceramic inserts 18 are set into these enlarged portions of thepassageway with the bottoms of the inserts bearing against the shoulders16. It will also be noted that the interior diameters of the inserts,when so placed, correspond to the interior diameter of the passagewaywhich lies intermediate the shoulders 16, so that there is provided,after the inserts are placed, a passageway through the entire length ofthe tube which is of substantially uniform diameter. These insertscontact the yarn passing through the tube at thepoints where the yarnchanges direction, and consequently at the points where the maximum wearoccurs.

' It is desirable in some instances to employ a filler, preferably anadhesive one, between the contacting surfaces of the inserts 16, or atleast the sides thereof, and the tube 12. This serves to provide a tightfit between the tube and the insert which is diflicult to achieve bymaking these elements with the exactness which would be required toprevent relative movement between them in the event such a filler wasnot employed. The use of the filler, if it is adhesive in nature, alsoprevents accidental yarn passing through the tube principally contactsthe tube.

A further object of the invention is to provide an improved carrier tubewhich contains ceramic inserts to take wear at the points or areas wherethe yarn principally contacts the tube, and which also comprises a steelsupport for the ceramic inserts which protect the ceramic and permit thetube to be fastened into the knitting machine and subjected tovibrations and shocks therein without fracturing the ceramic inserts.

One form of the present invention is illustrated in the accompanyingdrawings and described in more detail hereinafter.

In the drawings:

Figure 1 is a side elevational view of a carrier tube according to thepresent invention, also showing in dotted lines the central passage'ofthe tube and the position. of the ceramic inserts at either end;

Figure 2 is a longitudinalsectional view on the line 2-2 of Figure l ofthe same carrier tube; and

Figure 3 is a top plan view of the carrier tube illustrated in Figure 1.

Referring to Figure 1, it may be seen that the carrier tube, generallyindicated by the numeral 10, comprises an elongated annular tube 12which is preferably made of steel, although'other rigid metals ormaterials may be employed. The tube comprises a central passage 14 lReferring to Figures Z and 3, it may be seen that throughout the lengthof the tube, through which yarn is passed whenthe tube is "assembled inknown manner on 'a knitting machine. It maybe seenfrom Figures 1' and 2that the walls of the'tube' at the upper and lower ends arereducedinthickness to provide a shoulder 16,

and consequently, to e'nlarge'the diameter of the central passage 14outwardly of the shoulders 16. 1 r a displacement of the inserts.

A satisfactory ceramic for forming the insert according to thisinvention may consist of, the type of ceramic material which isdescribed in U.S. Patent No. 2,369,266 to Thurnauer, issued February 13,1945. It is not necessary, however, that the ceramic'have the electricalproperties therein described, although these may be desirable in someinstances. Ceramics having properties satisfactory for the manufactureof inserts according to this invention may be identified by thefollowing characteristics:

Hardness, Mobs scale AlSiMags, products of the American LavaCorporation, are satisfactory ceramic materials. U.S. Patent No.2,214,703 to Thurnauer describes ceramic materials satisfactory for thepresent invention.

It will be appreciated that the above characteristics are exemplary ofthe ceramic materials which may be employed, and that the invention maybe embodied in various forms other than that illustrated and describedspecifically above. i

a Having thus described the invention, what is claimed as new is: V

1. A carrier tube for guiding yarn in a knitting machine comprising arigid metallic cylindrical tube of substan- 7 tially greater length thanwidth and having a straight longitudinal axis, said tube being providedwith a central passageway of circular cross section extending throughoutthe length of the tube coaxially of the=longitudinal axis thereof, saidpassageway being enlarged at at least one end and of uniform diameterelsewhere along its length, the diameter of each such enlarged portion,being the same. and substantially constant throughout thelengththereof, a ceramicinsert fof annular form' positioned in each suchenlarged portion of said-passagewaywith its central aperture concentricwith said central passageway, both the external and internal di'ameterof; said insert i being essentially uniform along the length thereof,the

former being not greater than the diameter of the enlarged portion ofsaid passageway and the latter being the same as the uniform diameter ofsaid passageway exclusive of said enlarged portion, said insert beingsubstantially completely contained within the corresponding enlargedportion of said passageway. i

2. A carrier tube as claimed in claim '1 in which the enlargements ofsaid passageway provide annular shoulders at right angles to the axis ofsaid passageway which bear against the inner ends of said inserts.

3. A carrier tube as claimed in claim 2 in which a filler is placedbetween at least some of the contacting surfaces of said inserts andsaid tube.

4. A carrier tube as claimed in claim 3 in which said filler is anadhesive.

References Cited in the file of this patent UNITED STATES PATENTS BarlowDec. 31, Houghton Aug. 12, Scott Feb. 24, Amon Dec. 29, Weisbecker Dec.7, Feustel Aug. 9, Kannegieter Jan. 31, Weisbecker Sept. 10, Rowe Jan.6, Jauch Nov. 9, Barrett Jan. 1, Kaufmann July 31,

